1. Field of the Invention
The present invention relates to a magnetic recording powder having a low Curie temperature and a high saturation magnetization which powder is suitable for use in forming a magnetic recording layer for a magnetic card, magnetic tape, magnetic disk or like magnetic storage medium.
2. Description of the Relevant Art
In general, as magnetic recording powders having a low Curie temperature, magnetic recording powders having a saturation magnetization (.sigma.s) of 8 to 10 emu/g, a Curie temperature (Tc) of about 150.degree. C. and a coercive force (iHc) of 5 kOe or greater have frequently been used as disclosed in, for example, Japanese Unexamined Patent Publication No. 3-124003.
The development of high density magnetic recording in recent years has been remarkable. Accordingly, a magnetic recording powder used to form a magnetic recording layer is required to have a higher saturation magnetization. However, the conventionally used magnetic recording powders cannot meet such demand because each has a low saturation magnetization of 8 to 10 emu/g.
Accordingly, the present inventors carried out research in order to develop a magnetic recording powder having a low Curie temperature (Tc) of about 150.degree. C., a coercive force (iHc) of 5 kOe or greater, and a high saturation magnetization (.sigma.s) and obtained the following results from such research which are hereinafter described.